Connection elements of this type are used especially for the connection of furniture parts such as wall plates and floor plates, for example, in shelving construction or fair (tradeshow) exhibit construction. Customary connection elements are angles, for example, which are affixed with screws or nails to the parts to be connected. This is time-consuming; and moreover, the component parts are irreversibly damaged in these customary connection systems by the screwing-in of the screws or the driving in of the nails. Also, the detachment of component parts once they are connected is problematic. In particular, in a frequent assembly and disassembly of building systems, for example, in fair or tradeshow exhibit construction, customary connection elements cause considerable disadvantages.